James A. Brass, Philip Riggan1, Vincent Ambrosia, Robert Lockwood, Robert higgins, 2
The Brazil/United States Fire Initiative was signed in 1992 as a means of cooperative research to reduce the extent and environmental impact of widespread burning within the tropical savannas and forests of Brazil. This integrated program combines assessment of fire environmental impacts, scientific exchange, management support and fire management demonstration in priority conservation areas. The Initiative is authorized by an Implementing Arrangement constituted under the Memorandum of Understanding for Forestry cooperation between the USDA Forest Service and the Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renovaveis (IBAMA), and the science and technology agreement between the United States and Brazil. Agencies currently participating include:
Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renovaveis
USDA Forest Service
Instituto Brasileiro de Geografia e Estatistica
National Aeronautics and Space Administration
Instituto Nacional de Pesquisas Espaciais
Agency for International Development
Conselho Nacional de Desenvolvimento Cientifico e Techologico
National Center for Atmospheric Research
Corpo de Bombeiros Militar do Distrito Federal
University of Washington
Universidade de Brasilia
Universidade de Sao Paulo
Centro de Pequisa Agropecuaria dos Cerrados
USDA Office of International Cooperation and Development
World Wildlife Fund
Fire is pervasive in central Brazil, but its consequences are known only in broad outline. Fire is used to clear broad expanses of tropical forest for shifting agriculture and cattle ranching. In the Atlantic forests of the southeast, fires threaten the dwindling native forests and established plantations of pine and eucalyptus. Across the 200 million hectares of the cerrado or tropical savanna, fires recur at intervals of two to four years, threatening wildlife and the biodiversity of the ecosystem. Together, agricultural and wild land fires are likely a major source of greenhouse gases that may be altering global climate.
A core project of this program is the "assessment of fire emissions and biogeochemical impacts in tropical savanna and forests of central Brazil." Under this project, measurements were taken during August 1994 to determine fire extent, energy release and emissions of carbon monoxide, carbon dioxide and particulates into the atmosphere. Aircraft measurements from a Lear jet aircraft as well as field samples were made over extended regions of the cerrado, including sampling of fires in dry scrub, moist forest and agriculture. Remotely sensed data of fire characteristics were derived from a four-channel multispectral scanner. Concurrently, air samples within the smoke plumes were taken for carbon monoxide, carbon dioxide, particulates and water vapor. In addition, grab samples were taken at various altitudes for analysis in the United States. One large (400 hectare) well instrumented prescribed burn was also completed during the field campaign. Differing vegetation types were burned to determine the impact of species and fire intensity on trace gas generation. The controlled burns allowed the measurement of other important characteristics such as above ground biomass and burning efficiency which help determine trace gas and particulate production.
The field campaigns lasted one month with over 100 fires sampled. These campaigns have produced the most extensive sampling of fires in Brazil, where infrared imagery and gas samples have coincidentally been collected. Initial results have shown a large variability in fire behavior, from large intense fires to very slow moving line fires. depending on vegetation type and climatic conditions. This fire variability is also evident in the measurement of trace gas flux with concentrations of carbon monoxide and carbon dioxide varying with smoldering and flaming stages. In addition, production of methyl bromide and methyl chloride has been documented in cerrado fires in lowland aress, where much of the burning activity is in the smoldering stage. These gases known for their destruction of ozone may play a significant role in ozone hole dynamics.
Ames-Moffett contact: James A. Brass
jbrass@mail.arc.nasa.gov
or tel: (650) 604-5232
Program office: U. S. Forest Service
1 U.S. Forest Service
2 Simco